[lvc-project] [PATCH] staging: vme_user: Validate geoid used for VME window address

[Aleksandr Mishin]

In tsi148_crcsr_init() value of vme_base used as 3rd parameter in
tsi148_master_set() call is calculated as 'vstat * 0x80000'. vstat value
can be set from module parameter "geoid" which can be any. In this case
the value of an arithmetic expression 'vstat * 0x80000' is a subject to
overflow because its operands are not cast to a larger data type before
performing arithmetic.

Add geoid validation to prevent overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: d22b8ed9a3b0 ("Staging: vme: add Tundra TSI148 VME-PCI Bridge driver")
Signed-off-by: Aleksandr Mishin <amishin at t-argos.ru>
---
 drivers/staging/vme_user/vme_tsi148.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/vme_user/vme_tsi148.c b/drivers/staging/vme_user/vme_tsi148.c
index 2ec9c2904404..b601d2b20bed 100644
--- a/drivers/staging/vme_user/vme_tsi148.c
+++ b/drivers/staging/vme_user/vme_tsi148.c
@@ -2119,7 +2119,7 @@ static int tsi148_slot_get(struct vme_bridge *tsi148_bridge)
 		slot = ioread32be(bridge->base + TSI148_LCSR_VSTAT);
 		slot = slot & TSI148_LCSR_VSTAT_GA_M;
 	} else {
-		slot = geoid;
+		slot = geoid & TSI148_LCSR_VSTAT_GA_M;
 	}
 
 	return (int)slot;
-- 
2.30.2